Answer is: calcium and strontium have same number of valence electrons.
Beryllium, magnesium,calcium and strontium are alkaline earth metals. The elements have very similar properties. Alkaline earth metals have in common an outer s- electron shell (two electrons).
Electron configuration of calcium atom: ₂₀Ca 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²; calcium has two valence electrons (4s²).
Atomic number of calcium is 20, it means that it has 20 protons and 20 electrons, so atom of calcium is neutral.
Strontium electron configuration: ₃₈Sr 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶5s²; two valence electrons is 5s² orbital.
The question is incomplete, the complete question is;
The compound magnesium nitrate is a strong electrolyte. Write the reaction when magnesium nitrate is put into water:
Answer:
Mg(NO3)2(s)--------->Mg^2+(aq) + 2NO3^-(aq)
Explanation:
When we say that a compound is a strong electrolyte, we mean that that the compound dissociates completely in solution to form its ions.
This means that all strong electrolytes attain 100% dissociation of the solid in water according to its stoichiometric equation.
For magnesium nitrate, the reaction equation is;
Mg(NO3)2(s)--------->Mg^2+(aq) + 2NO3^-(aq)
Answer:
The first one is correct, 4.03 x 10^24.